The functions of copiers and printers have been extended nowadays, and with this, there is a demand for a toner that shows satisfactory fixability to plain paper in a high-speed printing process. At the same time, there is a demand for a toner that shows uniform and high glossiness in output onto heavy paper, such as glossy paper, in a low-speed printing process. Thus, in order to form satisfactory images even if the fixing conditions are varied and are hard, waxes contained in toners have been improved. However, when high-speed printing or output onto heavy paper is repeated, the wax contained in a toner contaminates the inside of an image forming apparatus and thus causes another problem. Accordingly, there is a demand for a toner that can prevent contamination of the inside (in particular, near the fixing device) of an apparatus even in use for a long time at high-speed printing or output onto heavy paper.
PTL 1 proposes a toner provided with excellent fixability by including a wax that has a low melting point and a sharp melting property by containing a high content of n-paraffin. PTL 2 proposes a toner provided with excellent hot offset resistance by regulating the average number of carbon atoms of hydrocarbon components of a wax. PTL 3 proposes a toner showing excellent fixability even on heavy paper by using a wax having an endothermic peak observed by DSC in a particular range.
However, though the toners described in PTLs 1 and 2 are excellent in fixability, the prevention of the inside of an apparatus from being contaminated in the fixing process is still insufficient. The toner described in PTL 3 can inhibit contamination of the fixing roller, but sufficient improvement effect is not obtained for inhibiting contamination of the insides of peripheral members of the fixing device.